Contact device for cross bar switches



Nov. 6, 1956' Filed June 14, 1955 Hg. 7 b 4 G. E. O. HOLMQVIST ET AL CONTACT DEVICE FOR CROSS BAR SWITCHES 5 Sheets-Sheet l Nov. 6, 1956 c. E. o. HOLMQVIST ET AL 2,769,380

CONTACT DEVICE FOR CROSS BAR SWITCHES 3 Sheets-Sheet 2 Filed June 14, 1955 M M MW VD M w HM ym M12 mm map k m w lR RK f r r w 6B Nov. 6, 1956 G. E. o. HOLMQVIST ET AL 2,769,880

CONTACT DEVICE FOR CROSS BAR SWITCHES Filed June 14, 1955 3 Sheets-Sheet 3 f/vvslvroks 66R) ERIK 040;- Hours. war BE/VG'I' Fm/r 8x612 KL u/vz: ARA/E Ku/vr D/ETJCI/ 2r mu. M

flrramvEf United States Patent CONTACT DEVICE FOR CRU'SS BAR SWITCHES Gert Erik 0110f Holmqvist, Stockholm, Bengt Erik Bibi-h lurid, Hagersten, and Arne Kurt Dietsch, Enskede, Sweden, assignors to Telefonahtieholaget L M Ericsson,

Stockholm, Sweden, a corporation of Sweden Application June 14, 1955, Serial No. 515,502 Claims priority, application Sweden luly 9, 11 54 2 Claims. (61. 206-166} The present invention relates to cross bar switches and refers to a contact device comprising a number of parallel contact springs situated in the same plane and rigid contacts corresponding to said contact springs, preferably multiple contacts, and a lifting bar for direct or indirect actuation of the contact springs, said lifting bar putting the contact springs in contact with the rigid confacts. In a cross bar switch there are on one hand selecting bars for indicating a number of spring sets lying in a row along the selecting bar, and on the other hand there are operating bars forming actuating means for a number of spring sets lying in a row along the operating bar. Said rows cross each other and the spring set situated in the crossing point is common to the two rows which cross each other and will be actuated by the operating bar only when the selecting bar is in a determined position. A. lot of different constructions is to be found for transmitting the movement of the actuating means to the lifting bar. With regard to the large number of spring sets which are comprised in the multiple of a cross bar switch, it is necessary that the devices for indicating a spring set are simple, cheap, reliable and do not need considerable space.

This is obtained according to the invention on one hand by the lifting bar being movable in relation to the contact springs and on the other hand by an elastic lever being rigidly fixed to the lifting bar and arranged mainly in parallel with the contact springs, the free end of said elastic lever being moved by said selecting bar in a direction perpendicular to the contact springs and parallel with the plane of the contact springs, the lifting bar thereby being swung in the plane of the contact springs.

The invention will be more closely described with reference to the attached drawings.

Figs. 1a and lb show a contact device, in which the lifting bar actuates the contact springs directly, on one hand in un-actuated and on the other in actuated position.

Figs. 2a and 212 show a contact device, in which the lifting bar, by actuating a control spring, indirectly puts the contact springs in contact with the rigid contacts.

Fig. 3 shows a modification of the invention, the selecting bar thereby giving the lifting bar an initiating movement by a direct touch.

In Figs. la and 1b, 1 is a supporting sheet to which a spring set 5 together with other spring sets comprised in the same vertical row, but not shown on the drawing, are fixed. contact springs 51-50 and a lifting bar 6 of insulating material with a spring 7 fixed to the lifting bar belong to each spring set 5. Along the supporting sheet 1 there is a selecting bar 4 which is mounted at the upper and lower ends of the supporting sheet in bearing devices which are not shown on the figures. The spring 7 is rigidly squeezed on the lifting bar 6 and is turnably mounted in a hole 41 in the selecting bar 4. Between the selecting bar and the lifting bar the spring 7 forms an elastic lever. The lifting bar 6 is suspended on the upper contact spring 51 and is provided with holes 62-60 for the other contact springs.

The contact springs 51-50 rest in normal position with a pressure downwards in holes in a block 2 of isolating material, which block supports the rigid contact strips 21-20. The block 2 and the contact strips 21-20 and an operating bar 3 are common to a number of spring sets in a horizontal row of spring sets which are arranged along the operating bar 3. The lifting bar 6 is pressed against the support 11, when the selecting bar 4 is in normal position, but is swung forward against the support 31, when the selecting bar 4 is pulled down. In Fig. 1a the selecting bar 4 as well as the operating bar 3 are in rest position. In Fig. lb both are actuated and the contact springs 51-50 make contact with the strips 21-2 If the operating bar 3 is actuated, when the selecting bar 4 is pulled down, the lifting bar 6 does not swing forward against the support 31 but is pressed against the edge 32 of the operating bar. When the selecting bar 4 in Fig. 15 is lifted, i. e. it returns to its initial position, the lifting bar 6 is kept pressed against the armature 3 by the contact springs 51-50. The contact springs 51-50 remain in contact with the contact strips 21-20.

In Figs. 2a and 2b the contact springs 51-5'2 press upwards and are kept against the lower part of the holes in the block 2 by means of an additional spring 9 and an additional lifting bar 8 of insulating material. The movable lifting bar 6 with the elastic lever '7 is suspended on the spring 9 and is used for lifting the spring 9. In rest position the lifting bar 6 is pressed against the support 11 by means of the spring 7. When the selecting bar 4 is pulled downwards, the lifting bar 5 is swung round its suspension point, and its lower part is pushed against the support 31 on the opergting bar 3, if said operating bar is in rest position, or against the edge 32, if the operating bar is actuated. When the operating bar 3 lifts the lifting bar 6, the contact springs 51-50 follow the movement by their own power and make contact with the contact strips 21-20. When the selecting bar 4 has thereafter returned to its rest position, the situation shown in Fig. 2b is obtained. In Fig. 1 and Fig. 2 the support 11 is fixed to the supporting sheet 1. Fig. 3 shows how said support may be replaced by a support 42 which is fixed to the selecting bar 4. This causes that, when the selecting bar is pulled downwards, the support 42 will cooperate with the spring 7 and initiate the oscillatory movement of the lifting bar 6. Owing to this the lifting bar is prevented from being wedged between the contact springs, or from not starting to move because of the friction against the supporting sheet 1. In Fig. 3 the operating bar 3 has another embodiment and the block 2 as well as the spring set 5 has been arranged for 12 contact springs.

We claim:

1. A contact device for cross bar switches comprising a number of parallel contact springs situated in the same plane and rigid contacts corresponding to said contact springs, a lifting bar which is lifted by a movable actuating means and puts said contact springs in contact with the rigid contacts, and a movable selecting bar, which must be in a determined position so that the movement of the actuating means is transmitted to the lifting bar, characterized by the lifting bar being movable in relation to the contact springs and by an elastic lever, which is rigidly fixed on the lifting bar and arranged mainly in parallel with the contact springs and the free end of which is moved by said selecting bar in a direction which is perpendicular to the contact springs and parallel with the plane of the contact springs, the lifting bar being swung in the plane of the contact springs.

2. A contact device according to claim 1, characterized by a support being attached to the movable selecting bar, against which support the lifting bar is pressed by said elastic lever, when the selecting bar and the lifting bar are in rest position, and which support co-operates with the elastic lever, when the selecting bar is actuated, in order to swing the lifting bar in the plane of the contact springs.

No references cited. 

